Separation of oxygenated compounds with bisulfite adducts



Jam-13, 1953*. v. F. MICHAEL SEPARATION oF OXYGENATED coMEouNns WITH BISULFITE AnDUcTs Filed sept. 24, 1947 3 Sheets-Sheet l www l MM h` f., 0 mM nF. m Q M n vw SEPARATION OF OXYGENATED COMPOUNDS WITH BISULFITE ADDUCTS Filed sept. 24, 1947 Jan. 13, 1953 v. F. MICHAEL 3 Sheefs-Sheet 2 Jan. 13, 1 953 V. F. MICHAEL SEPARATION OF OXYGENATED COMPOUNDS WITH BISULFITE ADDUCTS Filed Sept. 24, 1947 3 Sheets-sheet s Paten! Agen! Patented Jan. 13,1953

UNITED STATES PATENT OFFICE SEPARATION OF OXYGENATED COM- POUNDS WITH BISULFITE ADDUCTSA Vesta F. Michael, Tulsa, Okla., assigner to Stanolind Oil and Gas Company, Tulsa, Okla., a corporation of Delaware ApplicationSeptember 24, 1947,`Serial No. 775,919

Claims. l

purifying alcohols, aldehydes, ketones, carboxylic acids, and phenolic compounds from mixtures thereof with hydrocarbons.

My invention broadly comprises a novel method for separating alcohols from solutions thereof in organic liquids by extracting the alcohols with an aqueous solution of aldehyde and/or ketonebisulflte addition products, By means of this step, in combination with other operations as hereinafter set forth, I am able to separatesolu- (Cl. MiO- 450) taining around 1% of an alkali-metal compound, such as potassium hydroxide or potassium l'iluoride, are used to hydrogenate carbon monoxide, a Water layer containing lup to ormore `of oxygenated compoundsand a hydrocarbonlayer containing up to or more of oxygenated compounds are produced under' the following approximate conditions:

Ternperature, 60G-650 F.

Pressure, 15G-300 lbs/in?, gage Space velocity, 10-20 cu. ft.v CO, measured vat 60 F. and one atmosphere, per pound of iron per hour tions of organic cxygenated compounds into 1C Q0 concentration in feedy 10-20% by v01. generically dissimilar groups, from which the pkg@ ral-,i0 in fle-@(12-3 individual components may then be conveniently Isolated' The tWo layers have been found to contain the Numerous methodsofo plepang Organic Oxy" o following oxygenated compounds, and others: genated compounds have been devisedand reo acetaldehyde, propiona'ldehyde, acetone, methported in the pm or om Many of the motooos anol, methyl acetate, butyraldehyde, ethyl aceproduce the desired products 1n substantially toto, ethyl methyl ketone, ethanoly n propyl 2Jl pure condition, or in such mixtures that sep- 00h01, methyl n propyl ketone n butyl alcohol. aration is comparatively simple by conventional N ethyl fontymto methyl n butyl ketone n pontyl means. Other methods, however, are less selecalcohol, n decyl alcohol, higher aliphatic a100 tive, and tend to lproduce complex mixtures. from noloy aootlo oold nronlonlo acid bntyrlo acid, 1 Wmoh the .lsolatlon of puro oompoooots 1s ox.' methylbutyric acid, valerie acid, S-methylvaleric ooodmgly dfooult- For example the oll'eot 0X1' acid, caprylic acid, Z-methylhexanoic acid capric dation of natural gas or of other hydrocarbon myrlstlo ooldI poll-nmC nolo Stoarlo acid, gases is potentially one of the cheapest sources 9;; nnonol' and nlgnor pnonols lThe hydrocarbons of oxygenotoo oompouoosf mod too moi-'hoo has in the product comprise virtually the entire range too'oforo boon Swoloo extonofoy Too rooo' of saturated and unsaturated hydrocarbons, from non producto however oro o' Complex-mman@ dissolved methane to high-melting waxes. The of the theoretically doivaolo organic oxygoootoo following table illustratbes the daily output of ma@ a l. "no "ein cpl l Y th 1 employing the new process to produce 6,000 oar- Ca led *159181 wpwot on ess W erom Cal reis per day (42 gallons per barrel) of gasolinebon monoxide and hydrogen are reacted 1n the moge hydrocarbons. presence of a suitable catalyst, such as iron or cobalt, produces primarily hydrocarbons, but in 40 l addition a small yield of oxygenated compounds. Aqueous phase More recently, a new and improved process Gal/day lfor the hydrogenation oi' carbon monoxide has -etalehyde 4,247 been developed which permits the use of the PIOpOHlldehi/'de 873 fluidized-catalyst technique. The use of this 45 ACGOIIB 5,170 new technique with a catalyst of suitable corn- MetalOl 333 position in combination with carefully chosen Butylaldehyde 1,231 conditions of temperature, pressure, and space Ethyl methyl ketone 2,171 velocity elves not only much greater space-time Ethanol 30,322 yields, but also products a more desirable ooilso n-Propyl alcohol 6,879 ing range higher octane number. In adn-Butyl alcohol '2,036 dition, relatively higher yields of oxygenated Il-Penlyl alcohol 504 compounds are produced. Acetic acid 8,609 ln one embodiment of the new process, for Propionic acid 3,217 example, vi-herein reduced iron catalysts con- Butyric acid 1,579

3 Hydrocarbon phase Aldehydes and ketones 3,964 Alcohols 4,492 Acids 3,629

It will be obvious to those skilled in the art that the isolation of individual components from such a complex mixture would be exceedingly diiiicult by any known methods. Simple, direct. fractional distillation of either the hydrocarbon phase or the aqueous phase is not feasible because of the numerous multiple-component azeotropes that are known to exist among the various constituents, and because of the tendency of certain of the compounds to react, decompose, or polymerize when such a mixture is exposed to elevated temperatures for considerable periods of time. Moreover, the literature discloses no selective solvent or solvents capable of effecting the separation of such mixtures into the individual components.

In this situation, a new and eiective technique for isolating the components of the water-soluble aqueous products has been devised, as described in my copending application, Serial No. 748,295, iiled May 15, 1947; but the recovery of the oilsoluble oxygenated products on a large scale has been considered virtually impossible, and serious consideration has been .given to the conversion or destruction of these compounds by means of solid catalysts at high temperatures to produce a liquid hydrocarbon product suitable for use as a motor fuel. Now, however, I have devised a unique, surprisingly simple, and effective technique, involving successive extractions, by which I am able to isolate a remarkably high proportion of the oil-soluble oxygenated products.

One object of my invention is to provide a method for separating and purifying mixtures of organic oxygenated compounds from mixtures comprised thereof. Another object of my invention is to provide a method for segregating mixtures of organic liquids comprising organic oxygenated compounds into generically dissimilar groups of compounds. A further object of my invention is to provide a process for recovering organic oxygenated com-pounds, such as alcohols, aldehydes, ketones, carboxylic acids, and phenolic compounds, from hydrocarbon solutions thereof, and in particular from hydrocarbon solutions resulting from the oxidation of hydrocarbon gases, or from the hydrogenation of oxides of carbon, in particular carbon monoxide. Another object of my invention is to produce a hydrocarbon product relatively free of oxygenated compounds. A still further object is to produce a motor fuel of relatively good odor and of improved stability with respect to antiknock rating. Other objects of my invention, and its advantages over the prior art, will -be apparent from the following de scription.

The term generically dissimlar groups of compounds occurring herein is to be understood as meaning groups having dissimilar chemical properties. Under this denition, alcohols and phenols are generically dissimilar groups; and ketones, aldehydes, and carboxylic acids are others.

The development oi my process arose out of my unexpected discovery -that alcohols can be separated from organic solutions thereof by extraction with an aqueous solution immiscible therewith comprising one or more bisulfite addition products (adducts) of aldehydes and/or ketones, and further that alcohols, aldehydes, and ketones can be removed simultaneously from organic solutions by extraction with an aqueous solution of a mixture of a water-'soluble bisulfite and bisulte addition products of aldehydes and/or ketones. Moreover, I also observed that the alcohols can be selectively separated from the resulting extract, containing alcohols and the bisulte addition compounds of aldehydes and/or ketones, by extraction with a water-immiscible solvent, after which the aldehydes and ketones remaining in the alcohol-depleted extract can be regenerated and removed, for example, by steam distillation. by addition of an alkaline material or a strong acid, or by subjecting the extract to a differential heat treatment, as disclosed 4in U. S. Patent 2,457,250.

On the basis of this discovery, I am now able to make a substantially complete segregation of, for example, a hydrocarbon solution containing alcohols, aldehydes, ketones, carboxylic acids, and phenolic compounds by a process which may include the following steps:

1. Extraction of alcohols, aldehydes, and ketones from the hydrocarbon solution by use of an aqueous extractant lsolution comprising a watersoluble ibisuliite and one or more addition productsl of a water-soluble bisuliite with aldehydes and/or ketones.

la. Alternatively, the hydrocarbon solution may be extracted simply with an aqueous solution of a water-soluble bisulte. Bisulte-carbonyl compounds are first formed and are extracted into the aqueous phase; the adducts then effect the extraction of alcohols into the aqueous phase.

2. Separation of alcohols from the resulting extract lby extracting with a selective solvent, such as a light hydrocarbon, an ester, or an aliphatic ether.

3. Steam distillation of the aqueous raffinate to regenerate and separate the aldehydes and ketones contained therein.

3a. Or alternatively, addition of a strong acid or an alkaline material -to the alcohol-depleted extract to break down the bisulite addition products and release the aldehydes and ketones.

4. Extraction of the hydrocarbon rainate from step l with an aqueous solution of a mild alkali. such as sodium carbonate, to separate carboxylic acids.

4a. Alternatively, all of the organic acids, both carboxylic acids and phenolic compounds'may be extracted concurrently with an aqueous caustic solution.

5. Extraction of the hydrocarbon rafnate from step 4 with an aqueous caustic solution, such an aqueous sodium hydroxide, tc separate phenolic compounds.

My process is suitable for lseparating alcohols from solution in virtually any organic liquid that is not completely miscible with aqueous bisuliite solutions and that is compatible with bisulte adducts in the sense that it does not react substantially with or have any substantial tendency to destroy aldehyde-bisuliite and ketone-bisulte addition compounds. Among such organic liquids may be cited aliphatic hydrocarbons in general, such as pentanes, pentenes, hexanes, hexenes, heptanes, heptenes, octane's, octenes, petroleum naphthas, and the like; alicyclic hydrocarbons, such as cyclohexane, cyclohexene, cyclopentane, methylcyclopentane, and the like; aromatic hydrocarbons, such as benzene, toluene, xylene, and the like; ethers, such as ethyl ether, isopropyl ether, butyl ether, ethyl butyl ether, and

the like; .and ",a'ldehydes andjflietoneazzirrgeneral. suchA as the` group set.I forth above.:V

Water-solubleVY bisu-ltes in Vgeneral are suitable for use in .steps 1 andflaof .my proces'syinclud'- ingbisulfites. of alkali metals, specificallyslithium, sodium,. potassium, rubidium, andrrcesum;"alka line-earth metals, such :as: calcium; barium;y and strontium; and ammoniumsand substituted .ammoniums, such as methylanmionium', diethylammonium, tris 2 hydroxyethylfl'ammonium, benzyltrimethylammonium, and the like; f but owingr'to the. lower costtand. greater `availability of lpotassium and'sodium bisu'lntes,.I ordinarily choose to use the latter two.

In step 1, the. extraction should beycarriedrout Within the pH range kin .which the bisul'te addition compounds with'aldehydes. and/or ketones are stable, ordinarily. between Yabout 2.2i. and 8, and preferablybetweenfaboutfpH=5fand'8; yFor thisreason, the pH of the streamfof extractant supplied tothe extraction. column'V in step; r1 should be adjusted Vasrequiredfby;additionzo an alkaline material, such as sodium hydroxide, or an acidic. material, preferably-sulfur. dioxide or sulfurous acid, or abuiering .agentfsuchf ase-an acid sodium phosphate.

For the.- most. eiectiveextraetiomof :aldehydes and 'ketones" from. the 'organiczphasein step-fl, the 'aqueous bisultefextracting solution acontact.- ingV each 'incrementi ofv therorganic.. phase-.should contain a quantity of' free:l bisultexzatleast equivalent Ito the Valdehydes and-.zketones .in @the organic-.phase increment; Preferably; however, the free bisulteshouldf. be :present inat,l least slight excess, and VI have'founclfithat 5.0'.to21`00% excess.. or more may',be':employedadvantageously to ,speedv up the extractionand'to reduce the size of equipment required;`

The aqueous bisulte. iextractingiisolution; employed in` step N1V may suitalily=` contain a. tota-libisulfite concentration',H includingN both :i free: and

bound bisulte, between-about 3. and-525 weight percent, calculated as. the anhydrousI bisulte salt, andy preferably between.: about 10 andwl`5 weight percent'. Excessively highfconcentrations are dicult to Work with, owing totheirztendency to cause crystallization or' gellin-g; dur-ingrthe -extraction step. On the.l other hand, very low;:con centrations.- wouldv makeV it necessary to employ excessive volumes of extractant. Eor'effectivefextraction of alcohols, the extractant( .solution should 'containbetween about 7 and 20;.weight percent of ketone-bisuliite andoraldehyde-bisuliite adducts, and preferablyfbetweenaabout -10 and .15 weight percent. The; adducts2.maycbe tanes, pentanes,.hexanes, and the like.; esters,

.solubilizers for the alcohols, causing: them also to 'transfer from the. organic. phaseinto theaqueous phase.v This solubilizing eiect depends; ...to some"extent,'on the molecular Weightrof Ithe.l aldehydes andketones. in the additionA compound. Bisulte additionproducts of aldehydes and'. ke.:- tones havinga distribution'of molecular Weights similar to the. distributionxof Vmolecular. Weights in the alcohols have been .found to vbe mosts'de'.- sirable. Preferably, therefore, means should be provided, as detailed in Example III below, for

yrecycling-a portion'of the adduct streamsffrom various points in my process, and. for recycling bisulte solution, regenerated, for example, by steam distillation` or by: heat treatmentvasfdis.- closedi-n my vcopending` joint applicationwith Walker, referred to. above. I have also 'found' it advantageous to incorporate a limited quantity, suitably upto about 10%, of a lower aliphatic alcohol, such as ethanol or methanol, or a quantity of a hydrophilic ester, such as ethyl acetate or. butylr acetate, in the bisulte-adduct. extractant solution used in step. 1, in order -to =re duce'the'tendency'of the adducts to precipitate and to permit the use rof higher concentrations of adducts.. Tov this end, I' may also .recycle a portioniof the step l extract directly to the-step 1 extractant..

The term hydrophilic est-er is to be understood as referring/to esters having a solubility .in-.water greater than. about 1% by weight.

The aqueous:.extract from step 1 contains al- Ydehydes. and/or ketones in chemical combination and alcohols in solution. The alcohols.may`be removed selectivelyv by extracting the solution withV a solvent thatis immiscible therewithxstep Light..hydrocarbons, such as. propane.. bu.-

` such, asethyl acetatebutyl acetate, methylv buadded'to the extractant stream enteringftheexe isfactorily. at temperaturesas 'lowf-as, 10? 1C. for l somewhat below, .the lower 1imitbeing1the Vtemperature at which freezing ofthef solutionzor precipitation of solids.v therefrom takes..,.place. The upper temperature limit-variesfsomewhat, depending onthe ketone contentof the organic solution and of the aqueous. extraetant solution. Ketone-bisulite addition products become.V :increasingly unstable at .temperatures above about 409. C. For satisfactory removal ofwketonesfrom tyrate,.and the. like; `and aliphatic ethers, such as ethylether.. n-propyl' ether, isopropyl ether,

'nfbutyl ether, isoamylether, and. the like, are

particularly suitable` for thisextraction.v

The steamdistillation (step 3.) to. regenerate ands'eparate aldehydes. and. ketones. from the alcohol-depleted aqueous solution resultingirom stepzshould ordinarily-be carriedl out at C. or above toaccelerate therelease ofthe aldehydes from. the' comparatively stable aldehydebisulte adducts. Alternatively. I mayheat thealcohoh depleted aqueousV solution from step 2 and extract thereleased ketones and aldehydes therefrom. at around .80 C. or above, using solvents` such; as

those employed. in step 2, and operatingjinpreszsure equipment if necessary to avoid volatilization losses.

Subsequent processing of the various fractions produced in the above steps Amay be carried out accordingto methods known inthe art. Specifractional distillation, azeotropic distillation, and/or extractive distillation to separate the individual components of the residual alcohol mixture. Similar distillation techniques arealso suitable for separating the aldehyde and ketone mixture obtained in step 3 or 3a, and for further purifying the several hydrocarbon rainate streams from various steps in the process, containing diminished proportions of oxygenated compounds. The hydrocarbon rainate streams -may alternatively or additionally be contacted with silica gel, activated alumina, or other adsorption agents to remove Substantially all oxygenated compounds therefrom. The aqueous solution of carboxylic acid salts resulting from step 4 may be treated with a strong acid such as sulfuric acid to regenerate the carboxylic acids, and the acids may then be further processed, as by fractional distillation. The same procedure is suitable for further processing the aqueous solution of phenolates resulting from step 5.

My invention will be more fully undertood from the following specific examples:

EXAMPLE I One hundred parts by Volume of a heptane solution of n-heptyl alcohol containing 0.402 gram-mole of the alcohol per liter, as analyzed by the Grignard method, were shaken fteen minutes at Llll-45 C. with 100 parts by volume of an aqueous 20% heptaldehyde-bisulte adduct solution, prepared by mixing 105 parts by Weight of heptaldehyde, 112 parts by weight of sodium bisulte, and 798 parts by weight of water. The phases were then separated and analyzed. The aqueous layer measured 102 parts by volume and contained 0.210 gram-mole of n-heptyl alcohol per liter, corresponding to 53.2 percent of the alcohol originally present in the heptane solution.

Subsequently, the aqueous layer was agitated minutes at Llil-45" C. with 100 parts by volume of alcohol-free heptane, and the phases were separated and analyzed. The heptane layer measured 101 parts by volume and contained 0.0730 gram-mole of n-heptyl alcohol per liter, corresponding to 34.5 percent of the n-heptyl alcohol in the aqueous layer prior to extraction with heptane.

EXAMPLE II A hydrocarbon phase resulting from the hydrogenation ofcarbon monoxide over a iluidized-iron catalyst, as described above, was Washed successively with Water to remove water-soluble organic oxygenated compounds and with dilute aqueous sodium carbonatek solution to remove organic acids. rEhe resulting washed hydrocarbon phase contained a mixture of oil-soluble aldehydes and ketones, together with 1.237 gram-moles per liter 'of mixedalcohols, as determined by the Grignard method.

One hundred parts by volume of the Washed hydrocarbon phase were agitated iivfteen minutes at l0-45 C'. with 100 parts by volume of an aqueous heptaldehyde-bisulfite adduct solution, prepared as described in Example I, and the phases were separated and analyzed. The aqueous layer measured 105 parts by volume and coh- Atained 0.785 gram-mole of alcohols per liter, corresponding to 66.6 percent of the alcohols present in the Washed hydrocarbon phase.

EXAMPLE III The following example illustrates the applica- :tion of my invention to the treatment of the Vhydrocarbon phase resulting from the hydrogenation of carbon monoxide by a process in which the catalyst and reaction conditions are chosen to --yield a high conversion to organic oxygenated compounds, as defined above.

In a preliminary operation, the stream of product vapors resulting from the hydrogenation of carbon monoxide is condensed at least partially and separated into a gas stream, an oil stream, and a Water stream. A convenient method for carrying out this separation is illustrated in Figure l:

k 'The product vapor stream flows through line I `may be introduced through line 1.

into heat interchanger 2, where the normally liquid constituents are condensed partially or completely, and the resulting mixture of gases, oil, and water flows through line 3 into knockout drum Il. The gas stream emerges from the latter through line 5, and is successively passed upward through scrubbers 6 and 9. The liquids from the knockout drum iiow through line I3 into sepalrator I ii, Where the phases are permitted to tion ofa hydrocarbon stream that has been partially or completely denuded of oxygenated compounds in a later stage of my process. scrubber 9 may be by-passed by valve l0 if desired. The scrubbed gases, now virtually entirely free of oxygenated compounds, emerge from the top of scrubber 9 through line I2, and may be returned to process or otherwise disposed of. By regulating the temperature within separator I 4, the distribution of oxygenated compounds between the oil and Water phases may conveniently be controlled as desired. I have observed that the higher the temperature within separator I4, the lower the concentration of oxygenated compounds in the aqueous phase.

" The oil phase from separator I4 is withdrawn through line I6 and combined with the bottoms emerging from scrubber 9 through line I l, and the mixture is passed through line I8 into the bottom of washer I9. The aqueous bottoms emerging from scrubber Ii through line 20 are introduced into Washer I9 at an intermediate point. and into the top of washer I Gis introduced a stream of fresh water through line 2|. As the `oil stream rises through Washer I9, it is therefore scrubbed successively with a dilute aqueous solution of oxygenated compounds and then with fresh water. Substantially all of the Water-soluble oxygenated compounds are thereby removed from the oil stream, which emerges through line 22 and is then further treated according to the process of my invention, in order to segregate oil-soluble oxygenated compounds therefrom.

The water stream from separator I4 is withdrawn through line 24a and mixed with the aque- 'ous bottoms emerging from washer I 9 through line 23a. rIhe aqueous mixture nows through line 21a to further processing steps, as described in my cci-pending application, S. N. 748,295, filed May 15, 1947.

Such further processing as disclosed in said copending application may be substantially as follows. vThe water stream from:.separato1"-l.4 :isy WithdrawnY through line 121m. and mixed; with; theeratedV at asreluxratio around 4.0311, and theztop.- temperature'. ismaintained below,r about' 175,- E; by suitable. adjustment'. of. .the feedand; bottom;

temperature. Under these conditions,distil1a. tion: dfA ai water stream 'containing 11: per cent distillables otherstban organic acids. gaVeLthefoL-v lowing results:

Nomadic Acidityof l distillables` overhead,

percent as acetic Qverhead vapor temperature, F. in bottoms nil/gal.

From the itop of thezfractionating column; vapors',

pass ntocondenser:.32a andthe condensate, ,comprising; primarily.: alcohols, alde'hydes. ketones and. water flowstnto.'reiluxz'bottlez` 33a; Parti.- of the condensate: is refluxed. to the top :ofocolumn 30.-:through valve=34fand1 .theremainders taken olxthrough valve 35a; pump. 36m-and linefftla;`

'I'hez bottom stream.;from.;fractionator.- 31mv con.-

tainst'acids', while; `as shown :in thei above table,A

theacidity of. the overheadA is relatively negligible.

Thayalcohol, aldehyde; and ketone; stream.; in line: 31a: isintroduced into. fractionating column Aeq.uipped with reboilerv I-Izd-a. Abottom streamcomprising: water., n.-butyl alcohol and .high boilers4 is: removed. from the bottom .cfr columnsA.

Theoverhead.fromvcolumnA comprising n-butyl alcohol and lower boilers passes through.- condenser I'Ha into receiver H2a, and out through valve ll3a where the stream is divided, part. of it being'reuxedto column A and. the-remainder passing into column B, equipped withreboiler 13M., for. further fractionation. Erom the bot.- tom of. column B., a .streamcomprising butyraldehydeiand higherboilers is withdrawn.` Fromthe topof column B aV stream comprising mainly methanoLacetone and lower boilers is-withdrawn through condenser [21a into receiver VI22aand out through valve |2311- where the stream is d.- vided, part of it beingrefluxed.- to columnB.. .The lower boilers withdrawn in, this .manner include acetaldehyde. and propionaldehyde The condensedstream from the top of column B may be redistill'ed in further columns (not shown) to.

separate acetaldehyde and propionaldehyde, re-

spectively, from other nonacidic components,V such as acetone and' methanol. Thus, aldehydes boiling not 'higher than propionaldehyde are separated" from nonacidic components; suchas butyraidehyde and ethyl methyl. ketone, in column B.v

The hydrocarbon` stream from washer'fll 9" '(Fig ure 1') flows through line 2-2 into pump 23 (Figure 2)`. Aand from there vrt-hrou'glrli'ne 2ll'intorextractorl 25, Where it risescountercurrenttoa downwardflowingv aqueous solution of sodiumbisulte and bisulte addition products of` aldehyd'esand ketones at atemperature around C.V The free so'diumfbisulflte addsto the= aldehydes and ketones, giving productswhich are transferred yinto the aqueous phase; and the'- bisullteaddition compounds actas solubilizers forthealcohols,

10 permitting them also to betransferred into the aqueous phase.

The aqueous extract emerges from the bottom of extractor 25 through line 25 and valve 2, and is transferred Aby pump 28 through line 29 into the top of extractor 35, in which it flows down Ward counter-currentto a stream of pentane atv a temperatureY around 20 C. The alcohols' are thereby selectively extracted from the aqueous stream. The'pentane extractv emerging fromthe top of extractor flows through line 3l, heater 32 and line 33 intok an intermediatev pointer stripper Sil.V Heat is supplied to the stripper by reboiler 35. The' pentane is taken off overhead through condenser 35 to separator'l, from which a portion is reuxed to the stripper through valve 38, and the remainder is recycled through valve. 39, line 4U, pump IH, and line 42 to the bottom 0f' extractor 3D, makeup. solvent being added as re-y pump 49, by which it is transferred through. line 5) into heater 5I. Therein, the stream isheated to a temperature of about 807 C. or above, and is.

discharged through line 52 into stripper 53,

equipped with reboiler 54. In the stripper, the;

aldehydes and ketones are released from combination with the bisuliite, and are taken off overhead in admixture with water vapors through condenser 55 into separator 55. The aqueous phase from separator 55 is refluxed to stripper 53, and the water-insoluble phase, comprising primarily aldehydes and ketones, is withdrawn through line 5? to storage or further processing, by fractional distillation, for example,

A stream ofv regeneratedv bisulte solution emerges from the bottom of stripper 53,through line 58 and cooler 59, and is recycled to extractor 25 through line 63, line'SI, pump 62, and line 63. Makeup bisulfide is added to the recycledstream as required through line 64, andthe pH of the.

bisulte stream is'adjusted, preferably -to betweenv 5 and 8, by addition of sodium hydroxide or sulfurous acid through line 65.

The ketone and aldehydebisulte adductsthat are required to solubilize the alcohols in extractor 25 are supplied to the regenerated bisulflte solution entering the topA of the extractor through line 53V by adding thereto portions of other streams from various points in the process. A portion of the stream emerging from extractor 25 through line 25, containing the desired adducts, plus free bisultes' and alcohols, may thus be withdrawn through line and valve 61 and` introduced through line 5I. into pump 52. Similarly, a portion of the bottoms .emerging from extractor 35 through line 41, containing the desired adducts and free bisulte, may be withdrawn through line 8rand valve 65 and recycled by way of'line 10, linel and pump '52. By suit.-

ably vregulating theproportions ofv these various.

l1 flowing aqueous 7 percent sodium carbonate solution, introduced through line |55. In this extractor, sodium salts of the carboxylic acids are formed, and are dissolved in the water phase. The aqueous solution flows from the bottom of extractor |04 through line |36, pump |01, line |08, heater |08, and line H6 into stripper at an intermediate point. Dissolved hydrocarbons are stripped out of the solution by reboiler ||2 and are taken overhead in admixture with Water vapor through condenser ||3 into separator I |4, from which the aqueous phase is recycled to the stripper and the hydrocarbon phase is Withdrawn through pump ||5 and line ||6 and combined with the hydrocarbon stream issuing from the top of extractor |54 through line Il?. The stripped water solution from stripper is withdrawn through line H8, cooler ||9, and line |25, and is then acidiiied, preferably with sulfuric acid, added through line l2 The acidiiled mixture flows into an agitated reaction vessel |22, where it is cooled by a stream of cold water |23 flowing through jacket |24. Carbon dioxide produced by the acidification is allowed to escape through vent line |25. The acidied liquid Hows from the bottom of reactor |22 through seal line |26 into knockout drum |21, where any remaining gases are separated and vented through line |28. From the bottom of knockout drum |21, the liquid emerges through line |29 and is transferred by pump |36 through line |3| into extractor |32 at an intermediate point. Into the bottom of the extractor is introduced through line |33 a solvent for fatty acids, which flows upward through the downward-flowing aqueous stream and extracts the fatty acids therefrom. Suitable solvents are aliphatic ethers, such as isopropyl ether, butyl ether, and the like; aromatic hydrocarbons, such as benzene, toluene, and the like; esters, such as ethyl acetate, butyl acetate, methyl butyrate, and the like; and high-boiling Wood-oil fractions. Through line |34 at the top of the column is introduced a stream of fresh water, which washes any entrained or dissolved inorganic acid from the extract. The washed extract, comprising solvent and fatty acids, emerges through line |35 at the top of extractor |32, and is sent to storage 0r to further processing to isolate the Various components of the mixture. The exhausted aqueous stream emerging through line |36 at the bottom of extractor |32 is discarded.

The hydrocarbon streams in lines ||6 and ||1, containing small proportions of phenolic compoundaare combined in line |31, and are transferred by pump |38 through line |39 into extractor |46, where they flow upward countercurrent to a downward-flowing aqueous l0 percent sodium hydroxide solution, introduced through line |4 In this extractor, sodium phenolates are formed, and are dissolved in the Water phase. The aqueous solution` flows from the bottom of extractor |46 through line |42, pump |43, line |44, heater |45, and line |46 into stripper |41 at an intermediate point. Dissolved hydrocarbons are stripped out of the solution by reboiler |48 and are taken overhead in admixture with water vapor through condenser |46 into separator |56, from which the aqueous phase is recycled to the stripper and the hydrocarbon phase is withdrawn through line |5| and combined with the hydrocarbon stream issuing from the top of extractor |46 through line |52.

The combined hydrocarbon streams, now ccntaining only minor proportions of oxygenated compounds, flow through line |53 into pump |54,

12 and are transferred thereby through line |55 into the bottom of washer |56. The hydrocarbons pass upward through the Washer countercurrent to a stream of Water, introduced at the top through line |51, which scrubs out any dissolved or entrained caustic material. The Wash 'water from the bottom of the washer is discarded through line |58. The hydrocarbons emerge from the top of the washer through line |59, and are sent to storage or to further treatment, such 'as fractional distillation.

The stripped Water solution from stripper |41 is withdrawn through line |60, cooler |6|, and line |62, and is then acidied, preferably with sulfuric acid, added through line |63. The acidifed mixture flows into an agitated reaction vessel |64. where it is cooled by a stream of cold water |65 flowing through jacket |66. The reaction vessel is vented through line |61. The acidied liquid flows from the bottom of reactor |64 through seal line |68 into knockout drum |69, where any entrained gases are separated and vented through line |10. From the bottom of knockout drum |69, the liquid emerges through line |1| and is transferred by pump |12 through line |13 into extractor |14 at an intermediate point. Into the bottom of the extractor is introduced through line |15 a solvent for phenolic compounds, which flows upward 'through the downward-flowing aqueous stream and extracts the phenolic compounds therefrom. Suitable solvents are aromatic, naphthenic, and saturated aliphatic hydrocarbons, such as benzene, toluene, cyclohexane, methylcyclopentane, hexanes, and octanes. Through line |16 at the top of the column is introduced a stream of fresh Water, which Washes any entrained or dissolved inorganic acid from the extract. The Washed extract, comprising solvent and phenolic compounds, emerges through line |11 at the top of extractor |14, and is sent to' storage or to further processing to isolate the various components of the mixture. The exhausted aqueous stream emerging through line |18 at the bottom of extractor |14 is discarded.

While the foregoing examples illustrate the preferred forms of my invention, it will be understood that departures may be made therefrom within the scope of the specification and claims. In general, it can be said that any modifications or equivalents that would ordinarily occur to those skilled in the art are to be considered as lying within the scope of my invention.

In accordance with the foregoing specification, I claim as my invention:

1. In a process for separating and recovering generically dissimilar groups of organic oxygenated compounds from a hydrocarbon solution containing an oil-soluble carboxylic acid and comprising a preferentially oil-soluble alcohol and at least one carbonyl compound selected from the group consisting of aldehydes and ketones.

the steps which comprise extracting said hydrocarbon solution with an aqueous extractant solution comprising an alkali-metal bisullite and a vsolubilizer for said preferentially oil-soluble alcohol consisting essentially of a bisulfite addition product of a carbonyl compound selected from the group consisting of aldehydes and ketones at a pH of from about 2.2 to 8.0; separating said preferentially oil-soluble alcohol from the resulting aqueous extract; heating at least a portion of the alcohol-depleted aqueous extract above the decomposition temperature of the bisulte addition products contained therein; and with-l agents-cc drawing and recovering at leasta portion of the carbonyl compounds regenerated thereby. Y

2. In a process for separating and recovering generically dissimilar groups of organic oxygenated compounds from a hydrocarbon solution containing an oil-soluble carboxylic acid and comprising a preferentially oil-soluble alcohol and at leastone carbonyl compound selected from the. group consisting of aldehydes and ketones, the steps which comprise extracting said hydrocarbon solution with an aqueous vextractant solution comprising Aan .alkali-.metal bisulte anda solubilizer for said preferentially oil-soluble alcohol consisting essentially of a bisulfite addition product of a carbonyl compound selected from the group consisting of aldehydes and ketonesV at a pH of from about 2.2 to 8.0; separating said preferentially oil-soluble alcohol from the resultingaqueous extract; heating at least a portion of the alcohol-depleted aqueous extract above the decomposition temperature of the bisulfiteaddition products contained therein; withdrawing and recovering at least a portion of the carbonyl compounds regenerated thereby; and recycling the depleted aqueous solution to the initial extraction step.

3. In a process for separating a preferentially oil-soluble alcohol from a hydrocarbon solution thereof containing water-soluble oxygenated compounds including oil-soluble carboxylic acids, the steps which comprise washing said hydrocarbon solution with water to remove said watersoluble oxygenated compounds therefrom, thereafter contacting the resulting water-Washed hydrocarbon solution containing said preferentially oil-soluble alcohol at a pI-I of from about 2.2 to 8.0 with an aqueous extractant solution immiscible therewith containing a solubilizer for said preferentially oil-soluble alcohol consisting essentially of an addition compound formed from a watersoluble bisulte and a carbonyl compound selected from the group consisting of aldehydes and ketones, allowing the resulting mixture to stratify into an oil and an aqueous layer, and thereafter withdrawing the aqueous layer containing said preferentially oil-soluble alcohol and removing said oil-soluble alcohol from the resulting aqueous extract by extracting the latter with a selective solvent for said oil-soluble alcohol.

4. In a process for separating a preferentially oil-soluble alcohol from a hydrocarbon solution thereof containiing oil-soluble carboxylic acids and at least one carbonyl compound selected from the group consisting of aldehydes and ketones, the steps which comprise washing said hydrocarbon solution with water, thereafter contacting the said water-washed hydrocarbon solution with an aqueous extractant solution immiscible therewith containing a water-soluble bisulfite at a pH of from about 2.2 to 8.0, stratifying and separating an aqueous extract containing said preferentially oil-soluble alcohol and bisulnte adduct of said carbonyl compound, thereafter removing said oil-soluble alcohol from said aqueous extract by extracting the latter with a selective solvent for said oil-soluble alcohol.

5. The process of claim 4 wherein the total bisulte, both free and combined, present in said aqueous extractant solution is between about 3 and 25 weight per cent, calculated as the anhydrous bisulte.

6. The process of claim 4 wherein said aqueous extractant solution comprises a water-soluble bisulte and bisulfite addition products of carbonyl compounds selected from the group consisting of aldehydes and ketones, said carbonyl compounds vhaving substantially the same composition with regard to identity and relative proportions as the carbonyl compounds in said hydrocarbon solution. y

7. A method for separating water insoluble alcohols, aldehydes and ketones from a mixture containing them and hydrocarbons which comprisesintroducing said mixture into an extraction zone, contacting said mixture in said zonewith anaqueous vsolution of a water-soluble bisul nte compound and of a water-soluble bisulte adduct (l) formed from a carbonyl compound selectd"from the group/consisting of aldehydes and ketones, withdrawing from -said zone an aqueous extract containing said alcohols, bisulfite adduct (1) and bisuliite adduct (2) of the aldehydes and ketones in said mixture, thereafter countercurrentlywashing said extract with a relatively low-boiling hydrocarbon to form an extract phase comprising hydrocarbons and said water-insoluble alcohols and an aqueous raffinate phase comprising said bisulflte adducts (l) and (2), and thereafter withdrawing the phases thus produced from the zone of contact.

8. A method for separating water insoluble alcohols, aldehydes and ketones from a mixture containing them and hydrocarbons which comprises introducing said mixture into an extraction zone, contacting said mixture in said zone with an aqueous solution of a water-soluble bisulte compound and of a water-soluble bisulte adduct (1) formed from a carbonyl compound selected from the group consisting of aldehydes and ketones, withdrawing from said zone an aqueous extract of said alcohols, bisulte adduct (l) and bisulfite adduct (2) of the aldehydes and ketones in said mixture, thereafter countercurrently contacting said extract in a separate extraction zone with a relatively low-boiling hydrocarbon to form an extract phase comprising hydrocarbons and water-insoluble alcohols and an aqueous raffinate phase comprising said bisulte adducts (l) and (2), and thereafter withdrawing the phases thus produced from the zone of contact.

9. In a process for separating a preferentially oil-soluble alcohol from a hydrocarbon solution thereof containing water-soluble oxygenated compounds including oil-soluble carboxylic acids, the steps which comprise washing said hydrocarbon solution with water to remove said watersoluble oxygenated compounds therefrom, thereafter contacting the resulting water-washed hydrocarbon solution containing said preferentially oil-soluble alcohol at a pH of from about 2.2 to 8.0 with an aqueous extractant solution immiscible therewith containing a solubilizer for said preferentially oil-soluble alcohol consisting essentially of an addition compound formed from a water-soluble bisulnte and a carbonyl compound selected from the group consisting of aldehydes and ketones, allowing the resulting mixture to stratify into an oil and an aqueous layer, and thereafter withdrawing the aqueous layer containing said preferentially oil-soluble alcohol.

10. A method for separating a water-insoluble alcohol and at least one carbonyl compound selected from the group consisting of aldehydes and ketones from a mixture containing said at least one carbonyl compound, hydrocarbons and said water-insoluble alcohol, which comprises introducing said mixture into an extraction zone,

15 contacting said mixture in said zone with a free water-soluble bisulte compound and with an aqueous solution of a water-soluble bisulfite adduct (1) formed from a carbonyl compound selected from the group consisting of aldehydes and ketones, withdrawing from said zone an aqueous extract containing said alcohol, said bisulte adduct 1) and a bisuite adduct (2) of said at least one carbonyl compound, thereafter countercurrently Washing said extract with a re1- atively 10W-boiling hydrocarbon to form an extract phase comprising hydrocarbons and said alcohol and an aqueous raffinate phase compris ing said bisulte adducts (l) and (2) and there?l after withdrawing the phases thus produced from the zone of contact.

VESTA F. MICHAEL.

REFERENCES CITED The following references are of record in the file of this patent:

16 UNITED STATES PATENTS Number Name Date 432,198 Guignard July 15, 1890 1,095,830 Ekstrom May 5, 1914 1,704,751 Luther et a1 May 12, 1929 1,838,032 Wiezevich et al. Dec. 22, 1931 1,894,097 James Jan. 10, 1933 2,080,111 Bump May 11, 1937 2,274,750 Soenksen et al Mar. 3, 1942 10 2,288,281 Huijser et a1 June 30, 1942 2,505,752 Burton May 2, 1950 2,552,564 King et a1 May 15, 1951 FOREIGN PATENTS 15 Number Country Date 472,545 Great Britain Sept. 23, 1937 OTHER REFERENCES Fischer: Conversion of Coal into 011s, pp. 241-246, published 1925 by Ernest Benn Ltd., London.

Fieser et al.: Organic Chemistry," pp. 209-208. Copyright 1944 by D. C. Heath and Co., Boston. 

1. IN A PROCESS FOR SEPARATING AND RECOVERING GENERICALLY DISSIMILAR GROUPS OF ORGANIC OXYGENATED COMPOUNDS FROM A HYDROCARBON SOLUTION CONTAINING AN OIL-SOLUBLE CARBOXYLIC ACID AND COMPRISING A PREFERENTIALLY OIL-SOLUBLE ALCOHOL AND AT LEAST ONE CARBONYL COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALDEHYDES AND KETONES, THE STEPS WHICH COMPRISE EXTRACTING SAID HYDROCARBON SOLUTION WITH AN AQUEOUS EXTRACTANT SOLUTION COMPRISING AN ALKALI-METAL BISULFITE AND A SOLUBILIZER FOR SAID PREFERENTIALLY OIL-SOLUBLE ALCOHOL CONSISTING ESSENTIALLY OF A BISULFITE ADDITION PRODUCT OF A CARBONYL COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALDEHYDES AND KETONES AT A PH FROM ABOUT 2.2 TO 8.0; SEPARATING SAID PREFERENTIALLY OIL-SOLUBLE ALCOHOL FROM THE RESULTING AQUEOUS EXTRACT; HEATING AT LEAST A PORTION OF THE ALCOHOL-DEPLETED AQUEOUS EXTRACT ABOVE THE DECOMPOSITION TEMPERATURE OF THE BISULFITE ADDITION PRODUCTS CONTAINED THEREIN; AND WITHDRAWING AND RECOVERING AT LEAST A PORTION OF THE CARBONYL COMPOUNDS REGENERATED THEREBY. 